A former Huntington Beach man serving a 10-year prison term for health care fraud is facing new charges of marketing and distributing a dangerous drug and marketing it as an “all-natural herbal” version of the sexual impotency medicine Viagra, authorities said today.

Phu Tan Luong, 55, who was convicted five years ago of 35 counts of health care fraud and five counts of money laundering, was charged Thursday with one count of delivery for introduction into interstate commerce of a misbranded drug, which is a misdemeanor, said Thom Mrozek of the U.S. District Attorney’s Office.

The same charge was filed against Luong’s 26-year-old daughter, Helene Ngoc Bich Luong, who is believed to be a Canadian citizen living in that country, Mrozek said.

The maximum sentence for the misdemeanor is one year in prison.

Luong and his daughter allegedly delivered the drug — called Vitalex — through their business Vitapro Inc., Mrozek said. He said Vitalex was variously advertised as “herbal sexual enhancement supplements” and “all- natural” versions of Viagra, Cialis or Levitra.

The drug contains the unregulated “Acetildenafil-analog,” which is similar to the active ingredient in brand-name erectile dysfunction medication, Mrozek said.

“We want to get the word out to not buy this stuff,” because it’s dangerous, Mrozek said.

Federal prosecutors allege the Luongs got Vitalex from China and have shipped it to Orange County and throughout the country.

The new charges stem from a U.S. Food and Drug Administration search warrant executed in April 2008 when authorities seized Vitalex from the Vitapro business and the Luongs’ Huntington Beach home, which has been seized by the federal government, Mrozek said.

Phu Tan Luong owned United Medical Supply until he was convicted in 2005 of submitting fraudulent claims to Medicare for electric wheelchairs and hospital beds that were unnecessary and, in some cases, not delivered to patients, Mrozek said. Medicare lost $14 million in the scam, the spokesman said.

Phu Tan Luong started Vitapro with the profits from his United Medical Supply scheme, and continued to run the company from prison with his daughter’s help, Mrozek said.

Phu Tan Luong, who is doing his time in Texas, is expected to be returned to Southern California for a June 7 arraignment on the new charge, Mrozek said.